According to one aspect, a glass-free pre-impregnated material includes a polybenzimidazole (PBI) sheet and a partially cured resin encapsulating the PBI sheet. According to another aspect, a process of forming a glass-free pre-impregnated material includes encapsulating a PBI sheet within a resin and partially curing the resin to form the glass-free pre-impregnated material. According to yet another aspect, a printed circuit board comprises a glass-free dielectric layer that includes a PBI sheet encapsulated within a cured resin.

A method for manufacturing a dual conductor laminated substrate includes providing a first laminate including a first insulating layer and a first conductive layer; defining a first trace pattern including one or more traces in the first laminate; providing a second laminate including a second insulating layer and a second conductive layer; defining a second trace pattern including one or more traces in the second laminate; defining access holes in the second insulating layer; at least one of depositing and stenciling a conductive material in the access holes of the second insulating layer; and aligning and attaching the first laminate to the second laminate to create a laminated substrate.

A multi-layered circuit board proofed against conductor loss or diminution when heated includes first and second circuit base boards. Each first circuit base board includes a first dielectric layer and a first wiring layer formed thereon and a first stepped paste block as a conductor formed in the first dielectric layer. The first stepped paste block is electrically connected to the first dielectric layer. Each second circuit base board includes a second dielectric layer and a second wiring layer, a second stepped paste block as a conductor is formed in the second dielectric layer. When pressed together for an electrical interconnection, the paste blocks are sealed and thus captive between the first and second circuit base boards.

A wiring board includes a resin insulating layer having a component mounting surface, first connection pads formed on the component mounting surface of the resin insulating layer, second connection pads formed on the component mounting surface of the resin insulating layer such that the second connection pads are surrounding the first connection pads, and a protruding part including a metal material and formed on the component mounting surface of the resin insulating layer such that a portion of the protruding part is embedded in the resin insulating layer and that the protruding part is positioned between the first connection pads and the second connection pads and surrounding the first connection pads.

A laminated wiring board includes a plurality of first wiring boards laminated on one another, a first insulating resin layer disposed between two adjacent first wiring boards among the plurality of first wiring boards, and a second insulating resin layer configured to cover side surfaces of the plurality of first wiring boards.

A metal-clad laminate that includes a metal foil with low surface roughness and in which the adhesion strength between a liquid crystal polymer film and the metal foil is high, the low transmission loss in a high frequency region is low, and the problems associated with warpage and adhesive leakage are alleviated. The metal-clad laminate includes the liquid crystal polymer film, an adhesive layer, and the metal foil, with the adhesive layer and the metal foil stacked on one surface of the liquid crystal polymer film.

A manufacturing method of a multilayer board includes: forming a metal core layer including a main body, an island portion, and four connection portions, the island portion having a substantially rectangle shape and being located in an opening formed in the main body, the opening having a substantially rectangle shape, the four connection portions connecting side surfaces of four corners of the island portion or side surfaces of vicinities of the four corners of the island portion to a side surface of the main body; forming a first insulating layer on the metal core layer and in the opening; and forming, in the first insulating layer, a hole reaching each of the four connection portions and removing at least a part of each of the four connection portions through the hole to electrically separate the main body and the island portion from each other

A resin composition of the present invention contains: a maleimide compound (A) having a maleimide functional group equivalent of 300 g/eq. or more, and a transmittance of 1% or more at a wavelength of 405 nm (h-line); a maleimide compound (B) having a maleimide functional group equivalent of less than 300 g/eq.; and a photo initiator (C) having an absorbance of 0.1 or more at a wavelength of 405 nm (h-line).

A printed circuit board includes an insulating body, a wiring structure at least disposed on the insulating body; and a shielding portion including a conductive via disposed around the wiring structure of the insulating body. The conductive via includes first and second metal layers having different degrees of magnetic permeability.

An electronic device includes a multilayer circuit board having a non-planar three-dimensional shape defining a membrane switch recess therein. The multilayer circuit board may include at least one liquid crystal polymer (LCP) layer, and at least one electrically conductive pattern layer thereon defining at least one membrane switch electrode adjacent the membrane switch recess to define a membrane switch. The electronic may further include a compressible dielectric material filling the membrane switch recess. The electronic device may also include at least one spring member within the membrane switch recess.